Access to a patient's lumen can be established by a variety of temporary and permanently implanted devices. However, despite several types of lumen access ports and devices proposed over recent years, body lumen access remains one of the most problematic areas in the treatment of patients requiring long-term access. Most simply, temporary access can be provided by the direct percutaneous introduction of a needle through the patient's skin and into a blood vessel. While such a direct approach is relatively straightforward and suitable for applications such as intravenous feeding, short term intravenous drug delivery and other applications which are limited in time, they are not suitable for hemodialysis and other extracorporeal procedures that must be repeated periodically and often for the patient's lifetime.
Haemodialysis patients commonly undergo a placement of one of the two, or both, widely accepted long-term vascular access options during the term of their treatment. It is estimated that 50% of hospitalization time of haemodialysis patients is related to problems of access to the vascular system of the human body.
On the one hand, WO 2005/023336 discloses a surgical placement of an arteriovenous synthetic graft connecting a patient's adjacent peripheral artery and vein to divert some of the arterial blood flow through the graft. The other is an arteriovenous fistula, a direct surgical connection between adjacent artery and vein with no synthetic conduit used. In both cases, the blood circulation is accessed with two needles inserted through the skin into either the synthetic graft in the former case, or the venous portion of an arteriovenous fistula in the latter scenario. Needle stick injuries and infections contribute to the loss of these types of accesses.
US 2006/0047249, by Shubayev and Elyav, proposes a percutaneous vascular access system. This system consists of a cylindrical device body having a pair of hollow nipples extending from the exterior to the interior and a rotatable inner core with two positions to open and close the connections. However, the fixation of such a device to the skin or other soft tissue of the body, i.e. as a tissue anchor according to US 2006/0047249, raises a number of problems, such as the danger of displacement during use caused by body movements or exposure to mechanic stress.
Bone implanted access devices have also be proposed. For example, WO 2007/051339 concerns an access port comprising a central cylindrical portion, and external and internal canal communicating through a valve. Here, the access port contains only one fluid canal and is destined to be implanted in a tooth-supporting bone.